The mod shouldn't require server side to install it but when I try to search item I just see a toast tells me "Not installed on server"
Screenshot: ilya.wdfiles.com/local--files/chesttracker-issue/2025-01-31_19.03.38.png

That (should) only appear if you installed Where Is It by itself, and not Chest Tracker.

Try downloading the mod again: https://modrinth.com/mod/chest-tracker/versions?l=fabric